Terminal block for slot connection of insulated conductors

ABSTRACT

A terminal block for slot connection of insulated conductors, in particular for telecommunication lines, compresses a number of terminals fixed in a flat-shaped holder. Each terminal is bent 180* around a transverse line dividing the terminal into a longer and a shorter part, the longer part being inserted in a through passage of the holder and the shorter part in blind recess. The insulated conductor is connected to a terminal of the terminal block by pressing it into a pair of slots which are running parallelly from a hole in the bent end of the terminal towards the ends of each of the parts. In order to prevent the terminal from sliding in its recesses there is provided an embossed stop in the longer part which stop snaps against a bottom edge of a cut-out in the holder when the terminal has been inserted in the holder.

United States Patent Hasselbohm [541 TERMINAL BLOCKFOR SLOT CONNECTION0F INSULATED CONDUCTORS [72] Inventor: Sune Sigurd Sixten IIasseIbohm,

I-Iagersten, Sweden [73] Assignee: Telefonaktiebolaget LM Ericsson,

Stockholm, Sweden 22 Filed: March 17, 1971 21 Appl.No.:125,301

[30] Foreign Application Priority Data Driscoll ..339/98 51 Nov. 21,1972 FOREIGN PATENTS OR APPLICATIONS 1,640,629 10/1969 Germany ..339/97R2,002,058 10/1969 France ..339/97R Primary Examiner-Joseph I-I. McGIynnAssistant Examiner-Robert A. I-Iafer Attorney-Plane, Baxley & Spiecens[5 7] ABSTRACT A terminal block for slot connection of insulatedconductors, in particular for telecommunication lines, compresses anumber of terminals fixed in .a flatshaped holder. Each terminal is bent180 around a transverse line dividing the terminal into a longer and ashorter part, the longer part being inserted in a through passage of theholder and the shorter part in blind recess. The insulated conductor isconnected to a terminal of the terminal block by pressing it into a pairof slots which are running parallelly from a hole in the bent end of theterminal towards the ends of each of the parts. In order to prevent theterminal from sliding in its recesses there is provided an embossed stopin the longer part which stop snaps against a bottom edge of a cut-outin the holder when the terminal has been inserted in the holder.

4 Claims, 10 Drawing Figures PKTENTEDNM 21 I972 SHEET 1 [1F 2 Fiji INVENTOR Sums SIGIIRD Snxrsn Hassflaomn HTTORNS'VS PATENTEBnum m2 3.703.700

' SHEEI 2 0F 2 INVENTOR Suhli Suzuap Slx'rEuHnSsELBoHM TERMINAL BLOCKFOR SLOT CONNECTION OF INSULATED CONDUCTORS This invention relates to aterminal block for slot connection of insulated conductors comprising anumber of terminals fixed in a holder. Previously known are terminalblocks, for example for telephone cables, which are designed in such away that the conductors of the cables can be connected without firstremoving the insulation and without the use of tightening screws. Forthis purpose the terminals are provided with a slot extending from ahole, the diameter of the hole being somewhat larger than the diameterof the insulated conductor and the width of the slot being somewhatnarrower than the diameter of a bared conductor. The connection iscarried out by threading the conductor through the hole and forcing itdown into the slot whereby the edges cut through the insulation. In thisway two contact surfaces are obtained and the conductor is retained. Thedisadvantage of a terminal of this kind is, among other things, that thediameter of the bared conductor varies somewhat, thus causingdifficulties in getting the proper width of the slot and the conductorfirmly retained. Furthermore the terminal cannot be made too thin or itwill affect the mechanical stability. An object of this invention is toprovide a terminal block having terminals made for slot connection,which give better contacts and are less sensitive to variations of theconductor diameters than is the case of earlier constructions and thisnew terminal furthermore gives lower costs of material. Thecharacteristics of the invention are evident from the appended claims.

The invention will be described more fully with reference to theaccompanying drawing in which:

FIGS. 1-3 show a terminal block according to the invention seen from thefront, from the side and from above respectively;

FIGS. 4 and 5 show two different embodiments of the terminals beingincluded in the terminal block according to the invention before thebending;

FIG. 6 shows the same terminal from an edge bent ready for use;

FIG. 7 shows in perspective the lower part of the terminal and FIGS.8-10 show a modified form of a terminal block according to the inventionin a front view, a side view and in a top view respectively.

In the FIGS. 1-3, 1 indicates a holder which suitably can be moulded inone piece from an insulating material. The holder is intended formounting a number of terminals 2, of which, for the. sake of simplicity,only one is shown. The holder is for each terminal provided with twoT-shaped recesses 3 and 4 located opposite each other, the recess 3running through the holder while the recess 4 is blind, i.e., runningonly a part way into the holder. According to the example the recessesare designed in the form of grooves but they can as well be designed ascavities in their whole length or part of it. In said recesses theterminals, for example designed according to FIG. 4, can be fixed afterbeing bent 180 along a transverse line dividing an oblong hole 6 whichis placed unsymmetrically, into two equally large parts, and then beinginserted with their longer and shorter bent parts respectively into therecesses 3 and 4 respectively. In order to decrease the risk of leakingcurrents between the different terminalsv these can be separated by ribs10. According to FIG. 4 the lower part of the terminal is designed inthe known manner with a slot 9 extending from a hole 8 for slotconnection of conductors from the lower part of the terminal block. Theterminal 2 is further provided with two slots 7a and 7b extending fromthe hole 6. At the upper part of the terminal the holder is providedwith a cutting-out 5 passing through the wall between the recesses 3 and4. The conductors are then connected to the upper part of the terminalsby forcing them down into the slots 7a, 7b via the hole 6. In this waythe edges of the slots cut through the insulation of the conductor andfour electric contact surfaces are formed. Consequently, a considerablygreater electric reliability will be obtained than in earlier usedconstructions and furthermore the mechanical strength is of courseimproved, in spite of the fact that the terminal can be madeconsiderably much thinner than in earlier constructions. In order toimprove still more the reliability it is furthermore suitable that thewidths of the two slots 7a, 7b are somewhat different, so that a goodcontact is obtained even if the diameter of the conductor is varyingsomewhat, which generally is the case in the practice.

In FIG. 5 a further embodiment of the terminal 2 is shown. Thus theslots 7a and 7b are extending from two separate holes 6a and 6b whichafter bending.will be located opposite each other. In this way a greatermechanical strength of the terminal will be obtained which in certaincases can be desirable even if the conductor then has to be threaded.

In order to prevent the terminal from sliding in its recess, for exampleupon removing an earlier connected conductor, and thus no longer takingthe right position in the holder, the terminal, as is apparent from theFIGS. 4,5,6 and 7 can suitably in its lower part be provided with anembossed stop 12 having a surface which is rising in the direction fromthe end of the longer part of the terminal in order to facilitate theinserting of it into the holder which is made possible by the resilientconstruction of the holder. As it appears from FIG. 1 the stop restsagainst the bottom edge of a cutting-out 11 in the lower part of theholder when the terminal has been fixed in the holder. By terminatingsaid surface of the stop by a surface 13 being approximatelyperpendicular to the terminal and placing this at a suitable distancefrom the bending axis of it the approximately perpendicular surface willsnap into the bottom edge of the cutting-out 11 when the terminal hasbeen inserted in its place in its recesses 3 and 4.

The FIGS. 8-10 show a modified form of the terminal block according tothe invention, in a front view, in a side view and in a top viewrespectively. The terminals are placed in their position and are bentone more time The terminals can suitably be modified relatively to theexamples shown in the FIGS. 4-6 so that, for example, the form of thehole and the holes respectively in the two ends of the terminal isidentical. A terminal block according to the last mentioned example has,of course, not as long leakage current paths between the terminals asthe preceding one but for the use indoors the insulation resistance isin normal cases satisfactory.

lclaim:

1. A terminal block assemblage comprising: a flat shaped terminal holderof insulating material, said terminal holder being provided with aplurality of pairs of oppositely facing terminal recesses which areseparated by insulating material, a first recess of each pair passingcompletely through said terminal holder to provide a through channel,the second recess of each pair extending only part way through saidterminal holder to provide a blind channel, and cut-outs provided insaid terminal holder at a first edge thereof and opposite correspondingportions of said recesses whereby portions of said channels are exposed;and a plurality of terminals, each associated with a different one ofthe pairs of terminal recesses, each of said terminals comprising a flatstrip of conductive material bent at least 180 at a bend lineperpendicular to the longitudinal axis of the strip to provide a longerleg and a shorter leg, said shorter leg being disposed in said secondrecess, said longer leg being disposed in said first recess with the endthereof extending beyond a second edge of said terminal holder, theportion of said strip adjacent the bend line being adjacent said firstedge of said terminal holder and said cut-outs, an opening means in eachof said legs in the region of the bend line and slots in said legs, saidslots having a width narrower than said opening means and communicatingtherewith whereby a conductor can be connected to a terminal by beingpassed via said cut-outs through said opening means and pressed downinto said slots.

2. The terminal block assemblage of claim 1 wherein the slots of each ofsaid terminals are opposite each other and have different widths.

3. The terminal block assemblage of claim 1 wherein further cut-outs areprovided at said second edge of said terminal holder for exposing aportion of each of said first recesses, and wherein said longer legs areprovided with ramplike bosses for providing removal stops against theassociated further cutouts after a terminal has been inserted in a pairof recesses.

4. The terminal block assemblage of claim 1 wherein each of said longerlegs is bent back along another bend line perpendicular to saidlongitudinal axis and is provided with a further opening means in theregion of said bend line for accepting a conductor.

1. A terminal block assemblage comprising: a flat shaped terminal holderof insulating material, said terminal holder being provided with aplurality of pairs of oppositely facing terminal recesses which areseparated by insulating material, a first recess of each pair passingcompletely through said terminal holder to provide a through channel,the second recess of each pair extending only part way through saidterminal holder to provide a blind channel, and cut-outs provided insaid terminal holder at a first edge thereof and opposite correspondingportions of said recesses whereby portions of said channels are exposed;and a plurality of terminals, each associated with a different one ofthe pairs of terminal recesses, each of said terminals comprising a flatstrip of conductive material bent at least 180* at a bend lineperpendicular to the longitudinal axis of the strip to provide a longerleg and a shorter leg, said shorter leg being disposed in said secondrecess, said longer leg being disposed in said first recess with the endthereof extending beyond a second edge of said terminal holder, theportion of said strip adjacent the bend line being adjacent said firstedge of said terminal holder and said cut-outs, an opening means in eachof said legs in the region of the bend line and slots in said legs, saidslots having a width narrower than said opening means and communicatingtherewith whereby a conductor can be connected to a terminal by beingpassed via said cut-outs through said opening means and pressed downinto said slots.
 1. A terminal block assemblage comprising: a flatshaped terminal holder of insulating material, said terminal holderbeing provided with a plurality of pairs of oppositely facing terminalrecesses which are separated by insulating material, a first recess ofeach pair passing completely through said terminal holder to provide athrough channel, the second recess of each pair extending only part waythrough said terminal holder to provide a blind channel, and cut-outsprovided in said terminal holder at a first edge thereof and oppositecorresponding portions of said recesses whereby portions of saidchannels are exposed; and a plurality of terminals, each associated witha different one of the pairs of terminal recesses, each of saidterminals comprising a flat strip of conductive material bent at least180* at a bend line perpendicular to the longitudinal axis of the stripto provide a longer leg and a shorter leg, said shorter leg beingdisposed in said second recess, said longer leg being disposed in saidfirst recess with the end thereof extending beyond a second edge of saidterminal holder, the portion of said strip adjacent the bend line beingadjacent said first edge of said terminal holder and said cut-outs, anopening means in each of said legs in the region of the bend line andslots in said legs, said slots having a width narrower than said openingmeans and communicating therewith whereby a conductor can be connectedto a terminal by being passed via said cut-outs through said openingmeans and pressed down into said slots.
 2. The terminal block assemblageof claim 1 wherein the slots of each of said terminals are opposite eachother and have different widths.
 3. The terminal block assemblage ofclaim 1 wherein further cut-outs are provided at said second edge ofsaid terminal holder for exposing a portion of each of said firstrecesses, and wherein said longer legs are provided with ramplike bossesfor providing removal stops against the associated further cut-outsafter a terminal has been inserted in a pair of recesses.